Mercury switch



y 3, 1959 c. A ANDERSON '2,5os,986

MERCURY SWITCH Filed Dec. 21, 1946 Patented May 23, 1950 UNITED STATES PATENT OFFICE MERCURY SWITCH Carl Albin Anderson, Waukegan, Ill.

Application December 21, 1946, Serial No. 717,'234

Claims.

Ihis invention relates to a mercury switch, and more particularly to a momentary-contact mercury switch.

Many electrical devices or control systems require only momentary contact in order to initiate or suspend their operation, as for exampl the start and stop buttons frequently associated with motors. In the past it has been usual to make such momentary contact by manually operated mechanical means or directly by manual means. Since it is often desirable that such momentary contact exist for a predetermined time or that such contact be controlled from a distance, or for other reasons, there has been a need for an automatically operable monentary-contact switch which is simple in construction and which operates in an effective manner.

I have devised and am here disclosing and claiming a novel momentary-contact mercury switch which may be used to simplif th operation of electrical devices or control systems which require only mcmentary contact, as the start and stop buttons mentioned above. My new mercury switch also finds efiicient use as a Starter control for electrical systemssuch as ventilating systems, reversing circuits, time clock devices, and many types of electrical systems requiring low current devices to control heavy load circuits. My new switch operates by routng or directing a flow of mercury past a pair of spaced terininals when the switch is tilted, the mercury momentarily bridging the terminals in the course of the flow. This construction makes it possible to incorporate two pairs of spaced terminals in the switch, the mercury being directed alternately past each pair each time the switch is tilted. By locating the terminals adjacent a constricted portion of the channel through which the mercury fio'ws and by control of the amount of mercury used in the switch, the length of time the terminals will be bridged each time the switch is tilted can be accurately controlled. Other features and advantages of my invention will be apparent irom the following specication and from the drawings, in which:

Figure 1 is a side elevation of a mercury switch constructed in accordance with my invention; Figure 2 is a longitudinal horizontal section through the switch of Figure 1, taken on the line 2-2 of Figure 1; Figure 3 is a Vertical cross section taken on the line 3-3 of Figure 1; and Figure 4 is a Vertical cross section taken on the line 4-4 of Figure 1.

In Figure 1 a sealed envelope l El, which is preferably of elongated generally cylindrical shape and may be made of glass or other suitable material, acts as a housing 01' container for the operating parts of the mercury switch. A longitudinal partition l l is included within the envelope, said partition being integral with the envelope in the particular embodiment of my invention illustrated herewith, and extending longitudinall of said envelope, but terminating short of each end thereof, in such'manner as to form" a channel on each side of the partition, such channels being indicated as |2 and IS.

In the bottom of the envelope ill adjacent one side of one end thereof is the recess 14, and adjacent the opposte side of the other end of said envelope is the recess !5. As .may be seen best in Figure 2, each of the channels lZ and !3 communicates with the recess M, and the channel 13 terminates in the recess !4 and communicates with the recess !5. A quantity of mercury or other conducting liquid [6 is carried within the envelope, said mercury being adapted to be held in either of the recesses M or !5. As may be most clearly seen at !6 in Figure 4 the bottom of th envelope is so designed at each end that it slopes toward the recess at that end, and consequently when the switch is tilted (as for example if the left end of the switch as shown in Figure 2 were tilted out from the paper) the mercury would run through the channel [3, around the end of the partition l I and come to rest in a terminal position in the reces [5. Then if the switch were tilted in the opposite manner, the mercury 'would he caused to flow out of the recess !5, through the channel 12, around the end of the partiton !I and into the recess 14. Thus it will be seen that the partition l I directs the mercury to flow into a terminal position in accordance with the manner in which the envelope is tlted, and that as the envelcpe is tilted, the flow of the mercury or other conducting liquid is routed from one recess or terminal position to the other.

The partiticn il includes the protuberance Ha which cooperates with the protuberance oa in the inner wall of the envelope to form a con stricted` portion in the channel !2 intermediate the two terminal positions of the mercury, and similarly. the protuberance llb in the partition cooperates with the protuberance lOb in the en- Velone to form a con tricted portion in the channel iS intermediate the two terminal positions of the mercury. Leads ll and !8 are sealed into one end of the envelope, lead l'l running through the wall of the envelope and extending through the protuberance !na into the channel 12, and lead !8 running through the wall of the envelope and into the partiticn ll and extending through the prctuberance l la, into the channel l2. Such leads therehy form spaced terminals Ha and |8a adjacent the constricted portion of the channel [2. Simiiarly leads l and 20 enter the other end of the envelope and terminate in the spaced terminals !sa and 250; adjacent the constricted portion of the channel IS.

While I am herewith illustrating two pairs' of spaced terminals, it will be understood that my mercury switch could be operated equally well in certain applications with only one pair of terminals, or with more than two pairs of such terminals. Furthermore, in certain applications it may be desirable; to utilize a three* wire' circuit, and this may be done by' connecting' the two ter-- minals in the partition H, for example. Other variations of wiring or changes in the terminal arrangements will be obvious to those skilled. in the art, and it will be equally obvious that vary'- ing arrangements may be made without departing from the spirit of my invention, as for example changing the arrangem'ent of the termi'- nals so they themselves form the constricted portion of either or both channels. I have found however that the constr-uction shown in the drawing whereby the terminals emerge from the respective protuberances lend strength to the structure,. as well' as being, simple in construction.

In. operation, as the switch is tilted insuch manner as to bring the recess holding the mercury to a higher level than the empty recess, the mercury flows from the first mentioned recess and` the flow is directed by means of the partition H and the corresponding channel so that the mercury fiows through the constricted portion of the channeLand one of the pairs of spaced terminals is momentarily bridged as the mercury flows past this constricted portion. The length of time that the terminalsare bridged is dependent upon the area of the constricted. portion of the channels, and my switch may be constructed to cover a wide time range in this regard. When the switch is tilted in the other direction the mercury is routed through the other channel and the other pair of spaced terminals adjacent the constrictedportionoof the channel is momentarily bridged before the mercury returns to its first terminal position. In commercial use the mercury switch may be held in tilting clips of a relay, a clock lever, a thermostat, or any other appropriate tilt-ing device.

While I have shown and described certain embodimentsof my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the Construction and arrangement may bemade without departing from thespirit and scope of the inventionas disclosed in the appended claims.

I claim:

1; A- momentary-contact switch of'the character described, including: a sealed envelope adapted tobe tilted and having a conducting liquid therein and arecess adapted to contain said liquid adjacent each' of two opposite ends thereof; means within the envelope for directing said liquid to flow along one path into one of said; recesses when the envelope is tilted in one direction and to flow along another path into the' other recess when said envelope is tilted: in the opposite direction, such means comprising a partition forming an elongated straight channel parallel to the longitudinal axis of said envelope and. having a constricted portion; and spaced terminals adjacent said constricted portion and so spaced that they are only momentarily'bridged as'said liquid flows pastsaid constricted portion.

2; A mercury switch of the character described, including: an elongated sealed envelope adapted to be'tilted about a fixed axis and having a quantity cf' mercury therein and a recess adapted to contain said mercury adjacent opposite ends thereof; meanswithin the envelope.` for selectively-'directing said mercuryto flow into' one of said secesses in accordance with the manner in; which said envelope is tilted, such means comprising an elongated longitudinally arranged partition forming a channel on each side thereof, said channels being' approximately parallel to each other' for armajor portion of their length, and each channel communicating with said recesses and each channel having a constricted portion intermediate said recesses; and a pair of spaced terminals adjacent each constricted portion, each pair' of terminals being so spaced that they are momentarily bridged as said liquid flows past said respective constricted portion.

3. A mercury switch of the character described, including: an elongated sealed envelope adapted to be tilted and having a quantity of mercu-y therein, a first recess adapted to containsaid mercury adjacent one side of one end thereof; and a second recess adjacent the opposite side of the other end thereof; means within the envelope for selectively directing said mercury to flow into one of said recesses in accordance with the manner in which said envelope is tilted, such means comprising a, longitudinally arranged partition forming a first channel on one side thereof and a second channel on the other side thereof, said first channel terminating in said first recess and communicating with said second recess, and said second channel terminating in said second recess and communicating with said first recess, said channels being parallel to the longitudinal axis of said envelope throughout a major portion of their length, and each channel having a constricted portion intermediate said recesses; and a pair of spaced terminals adiacent each constricted portion, each pair of terminals being so spaced that they are momentarily bridged as said liquid flows past said respective constricted portion.

4. Apparatus of the character claimed in claim 3, wherein the bottom of the interior wall of said envelope slopes toward each recess adjacent each end of saidenvelope.

5. A momentary-contact switch of the charac ter described, including: a sealed envelope adapted to be tilted and having a conducting liquid therein; means within the envelope for directing said liquid to flow along one path into one terminal position. when the envelope is tilted in one direction and to flow along another path into another terminal position when said envelope is tilted in the opposite direction, such means comprising a partition forming a channel having a constricted portion, said channel being horizontal throughout a portion of its length when the envelope is in a level position andhav.- ing a recess at each of its ends; and spaced terminals adjacent said constricted portion and. so spaced that they are momentarily bridged as said liquid flows past said constricted portion.

CARL ALBIN ANDERSON.

REFERENCES CITED The following references are of record' in the file of' this patent:

UNITED STATES PATENTS Number Name Date 453,(318 Brown June 9, 1891 '712,134 Hutchinson Oct. 28, 1902 '754,496 Potter e Mar. 15, 1 904 1,083,580 Zenke Jan. 6, 1914 1,804,0 17 Mailey May 5,. 1931 2,155,689 Sherman Apr. 25, 1939 &194239 Weman -.Man 19, 1940 2,232,627 Olsen Feb.. 18, 1941 

